What's the difference between this bcd and the knighthawk air 2? Which is better?
The main important distinction is that the Knighthawk is a back inflate and the the Glide X a jacket. The Knighthawk will keep you more horizontal in the water and the Glide more vertical at the surface. Some trim weight in the back and avoiding over-inflating the Knighthawk will avoid any pushing forward at the surface. The Knighthawk will also give you a more streamlined profile and will not squeeze you at the sides, and it has greater lift: 44.9 lbs in all sizes except small which has 33.7 lbs. The Glide X has 22.5 lbs. in extra small, 29.2 lbs in small, 31.5 lbs. in medium, 33.7 lbs. in large and extra large, and 38.2 lbs. in extra extra large. Additionally, the ditchable weight in the Knigthhawk is 12 lbs. per pocket (except size small 10lbs) and the Glide X is 10 lbs. per pocket. Both are great BC's. If you need more lift and more ditchabel weight, then the Knighthawk is a better choice. The other factors are personal preference issues. Hope that helps!